The present invention relates to building heating and cooling systems, particularly as used in a residence, and performance monitoring apparatuses therefor.
Rather than failing suddenly and completely, the environmental control system which controls the temperature of the interior of a building may experience a performance degradation which may not be immediately noticed by the occupants of the building, and which may occur during a time period over which the performance of the system degrades continually, eventually leading to a complete failure. Often, building occupants notice the degradation in performance only when they sense that their environment is uncomfortably hot or cold, by which time the environmental control system may have completely failed. At this point, the occupants are left with an inoperable environmental control system, and must contact an appropriate repair facility to investigate the problem and make the appropriate repairs. Also, once the occupants notice that the system is not operating properly, they are left to their own devices to contact an appropriate repair facility to undertake repairs. Therefore, a considerable period of time may pass before the repair personnel are contacted and arrive to address the failure, during which time the occupants may be completely without heat or air conditioning.
In some cases, the gradual degradation of system performance, which may go unnoticed by the occupants, may be indicative of a problem which will eventually result in a sudden system failure or other types of concerns. For example, in some cases, if the refrigerant charge level of an air conditioning system drops to a level which is too low to adequately carry oil back to the compressor for lubrication of some interfacing surfaces therein, excessive wear or seizure of the compressor may result.
Further, many environmental control systems utilize a filter for cleaning the air which is heated or cooled by the environmental control unit. These filters require cleaning or replacement, usually by the occupants, after a period of use. A dirty filter restricts airflow through the unit, which inhibits the system""s ability to force air through the ductwork and interchange the air in the building. Often, replacement of the filter is neglected by the user, and the performance of the system consequentially degrades.
A way to identify environmental control system performance degradation before complete system failure occurs is thus highly desirable. Further, a way of automatically contacting the appropriate repair facility, so that personnel at the facility will become aware and initiate repair of the failing system is also desirable. Additionally, a reminder by which the occupants will be notified that the filter should be replaced or at least inspected, the filter having completed its anticipated normal use period, is also highly desirable.
The present invention addresses each of the above issues by providing notice to the occupants and, in certain embodiments, an appropriate repair facility, of a degradation in environmental control system performance.
The present invention provides an incipient failure indication apparatus for an environmental control system which includes a heat exchanger through which air flows and a temperature control thermostat. The indication apparatus includes an indicator or annunciator having an alarm in communication with a control board, the control board in communication with the thermostat. The alarm has a visual indicator and/or an aural indicator, whereby the attention of a person is attracted to the indicator upon activation of the alarm. A first temperature sensor is disposed on the upstream side of the heat exchanger and a second temperature sensor is disposed on the downstream side of the heat exchanger, whereby the temperature sensors respectively sense the temperature of the air upstream and downstream of the heat exchanger. The first and second temperature sensors are in communication with the control board, and the control board has means for comparing the temperatures sensed thereby. The control board also includes means for activating the alarm in response to recognizing a difference in temperatures sensed by the first and second temperature sensors which is one of greater than and less than a predetermined value.
An embodiment of the present invention may also provide means for activating a remote alarm upon activation of the alarm, whereby persons outside of a living space serviced by the environmental control system are notified of an incipient failure of the environmental control system.
Further, an embodiment of the present invention may also provide a timer and a reset switch in communication therewith, a filter service time indicator, and means for activating the filter service time indicator a predetermined period measured by the timer after the reset switch is activated.